Viscoelastoplastic model for predicting performance of asphaltic mixtures

TLDR: In this paper, a mechanistic model for predicting performance of asphalt mixtures in terms of crack propagation rate, fatigue life assessment, and permanent deformation characteristics is presented, based on stress evaluation by the finite element method and on a comprehensive viscoelastoplastic material law.

Abstract: A mechanistic model for predicting performance of asphalt mixtures in terms of crack propagation rate, fatigue life assessment, and permanent deformation characteristics is presented. The model is based on stress evaluation by the finite element method and on a comprehensive viscoelastoplastic material law. A critical octahedral shear strain is assumed to be the failure criterion. A computer simulation of the resilient and residual deflections of uncracked beams as well as a fatigue crack growth simulation of an initially cracked beam are performed. These results are then compared with laboratory tests performed at various load levels with varying periods of loading and unloading. The agreement between the predicted and the measured performance of the sand-asphalt mixture in terms of residual and resilient deflection, crack length versus number of load applications, and rest period effect on fatigue life is found to be quite good. The simulation is then applied to predict rutting parameters, fatigue life curves, and crack propagation rate versus stress intensity factor for the sand-asphalt mixture.